/*
 * Copyright (C) 2015 Square, Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package io.polaris.core.javapoet;

import java.io.IOException;
import java.lang.reflect.GenericArrayType;
import java.lang.reflect.Type;
import java.util.ArrayList;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;

import javax.lang.model.element.TypeParameterElement;
import javax.lang.model.type.ArrayType;

import static io.polaris.core.javapoet.Util.checkNotNull;

public final class ArrayTypeName extends TypeName {
	public final TypeName componentType;

	private ArrayTypeName(TypeName componentType) {
		this(componentType, new ArrayList<>());
	}

	private ArrayTypeName(TypeName componentType, List<AnnotationSpec> annotations) {
		super(annotations);
		this.componentType = checkNotNull(componentType, "rawType == null");
	}

	@Override
	public ArrayTypeName annotated(List<AnnotationSpec> annotations) {
		return new ArrayTypeName(componentType, concatAnnotations(annotations));
	}

	@Override
	public TypeName withoutAnnotations() {
		return new ArrayTypeName(componentType);
	}

	@Override
	CodeWriter emit(CodeWriter out) throws IOException {
		return emit(out, false);
	}

	CodeWriter emit(CodeWriter out, boolean varargs) throws IOException {
		emitLeafType(out);
		return emitBrackets(out, varargs);
	}

	private CodeWriter emitLeafType(CodeWriter out) throws IOException {
		if (TypeName.asArray(componentType) != null) {
			return TypeName.asArray(componentType).emitLeafType(out);
		}
		return componentType.emit(out);
	}

	private CodeWriter emitBrackets(CodeWriter out, boolean varargs) throws IOException {
		if (isAnnotated()) {
			out.emit(" ");
			emitAnnotations(out);
		}

		if (TypeName.asArray(componentType) == null) {
			// Last bracket.
			return out.emit(varargs ? "..." : "[]");
		}
		out.emit("[]");
		return TypeName.asArray(componentType).emitBrackets(out, varargs);
	}


	/** Returns an array type whose elements are all instances of {@code componentType}. */
	public static ArrayTypeName of(TypeName componentType) {
		return new ArrayTypeName(componentType);
	}

	/** Returns an array type whose elements are all instances of {@code componentType}. */
	public static ArrayTypeName of(Type componentType) {
		return of(TypeName.get(componentType));
	}

	/** Returns an array type equivalent to {@code mirror}. */
	public static ArrayTypeName get(ArrayType mirror) {
		return get(mirror, new LinkedHashMap<>());
	}

	static ArrayTypeName get(
		ArrayType mirror, Map<TypeParameterElement, TypeVariableName> typeVariables) {
		return new ArrayTypeName(get(mirror.getComponentType(), typeVariables));
	}

	/** Returns an array type equivalent to {@code type}. */
	public static ArrayTypeName get(GenericArrayType type) {
		return get(type, new LinkedHashMap<>());
	}

	static ArrayTypeName get(GenericArrayType type, Map<Type, TypeVariableName> map) {
		return ArrayTypeName.of(get(type.getGenericComponentType(), map));
	}
}
